In communication systems, a transmitter may encode data based on a coding scheme to obtain code bits, and further map the code bits to modulation symbols based on a modulation scheme. The transmitter may further process the modulation symbols to generate a modulated signal. Such a modulated signal may be transmitted via a communication channel, which may distort the transmitted signal with a channel response, and degrade the signal with noise and interference.
A receiver receives the transmitted signal and processes the received signal to obtain received symbols, which may be distorted and noisy versions of the modulation symbols sent by the transmitter. The receiver may then compute LLRs for the code bits (also referred to as bits) based on the received symbols. The receiver may then decode the LLRs to obtain decoded data, which is an estimate of the data sent by the transmitter.
The computation for the LLRs may be complex and computationally intensive. Furthermore, good decoding performance may require accurate LLRs. Accordingly, it would be desirable and useful to provide an improved system to compute LLRs efficiently and accurately.